TW201424860A - Substrate processing apparatus and substrate processing method - Google Patents

Abstract

The invention reduces the load on an exhaust device that applies suction to a cup body, and effectively prevents re-deposition of a process liquid that has been supplied to a substrate after the process liquid has been flung from the substrate. During processing of a substrate (W), a ring shaped cover member (5) covers a peripheral edge section of the upper surface of the substrate (W) held by a substrate holding section (3), and the central section of the substrate located radially inward from the peripheral edge section is not covered by the cover member and is exposed. A gap (G) is formed between a bottom surface (52) of the cover member and the peripheral edge section of the upper surface of the substrate held by the substrate holding section. When suction is applied to the internal space of a cup body (2) via an exhaust port (245), the air above the cover member enters the internal space of the cup body via the space surrounded by an inner circumferential surface (51) of the cover member, and the gap (G).

Description

Substrate processing apparatus and substrate processing method

The present invention relates to a technique of supplying a processing liquid to an edge portion of a rotating substrate and processing the edge portion.

In the process of the semiconductor device, the edge portion cleaning step is performed, and the semiconductor wafer to be processed (hereinafter referred to as "wafer" is rotated), and a processing liquid such as a chemical liquid is supplied to the edge portion of the wafer. Unwanted film or contaminants are removed from the edge portion. Such cleaning is referred to as bevel cleaning or edge cleaning.

Patent Document 1 discloses a liquid processing apparatus for performing edge cleaning. The liquid processing apparatus includes a vacuum chuck that holds the wafer in a horizontal posture and rotates around a vertical axis, and a nozzle that ejects a liquid to an edge of the rotating wafer; the cup surrounds the periphery of the wafer. A processing fluid that occupies the wafer; and a disk-shaped covering member that is adjacent to the top surface of the wafer and covers the top surface of the wafer and seals the top surface of the cup. A chimney-shaped suction pipe is provided from a central portion of the covering member, and a protruding portion that protrudes downward is provided at a position directly above the edge of the wafer in the covering member. Since the inner space of the cup is sucked to become a negative pressure, the downflow of the clean air flowing in the casing is introduced from the suction pipe, and the space between the top surface of the wafer and the bottom surface of the covering member flows toward the edge of the wafer. The inside of the cup body flows into the inside of the cup body by a narrow gap formed between the protrusion portion of the covering member and the top surface of the wafer. By this air flow, the mist of the chemical liquid scattered to the outside of the wafer is prevented from being attached again. The top surface of the wafer contaminates the top surface of the wafer (component forming surface).

However, since the covering member of Patent Document 1 covers the entire surface of the wafer, the flow path resistance from the inlet of the suction pipe to the cup is large. Therefore, if the inner space of the cup body is not strongly sucked, a gas flow of a sufficient flow velocity cannot be obtained at the narrow gap outlet portion.

[Practical Technical Literature]

[Patent Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. 2012-84856

The present invention provides a technique for reducing the load on the exhaust device of the suction cup and effectively preventing the treatment liquid supplied to the substrate from being scattered from the substrate and then adhering to the substrate again.

The present invention provides a substrate processing apparatus including: a substrate holding portion that holds a substrate horizontally; a rotation driving mechanism that rotates the substrate holding portion about a vertical axis; and a processing liquid nozzle that supports a top surface of the substrate held by the substrate holding portion a processing liquid is supplied to the edge portion; the cup body surrounds the periphery of the substrate held by the substrate holding portion, and the processing liquid scattered from the substrate is collected; the exhaust port is used for the gas for sucking the inner space of the cup; and the ring is used; a covering member having a bottom surface and an inner peripheral surface; wherein the covering member covers an edge portion of a top surface of the substrate held by the substrate holding portion, and the covering member is not covered with a radially inner side of the edge portion a bottom portion of the substrate is exposed; a gap is formed between the bottom surface of the top surface of the substrate held by the substrate holding portion, and the bottom surface of the cover member is located when the inner space of the cup is exhausted The gas above the inner space of the cup is introduced into the inner space of the cup through the gap from the space surrounded by the inner peripheral surface of the covering member.

In addition, the present invention provides a substrate processing method comprising the steps of: surrounding a cup a step of holding the substrate horizontally by covering the upper side of the substrate with an annular covering member around the substrate; and discharging the substrate to the vertical axis in a state where the inner space of the cup is exhausted and the substrate is rotated about the vertical axis a step of supplying a processing liquid to the substrate, and performing a liquid processing step on the substrate; wherein, when the substrate is subjected to liquid processing, the covering member covers an edge portion of a top surface of the substrate held by the substrate holding portion, the covering member The central portion of the substrate that is located radially inward of the edge portion is not covered and exposed, and a gap is formed between the bottom surface of the covering member and the edge portion of the top surface of the substrate, by the inner portion of the cup The space is exhausted, and the gas located above the covering member is introduced into the inner space of the cup through the space surrounded by the inner peripheral surface of the covering member and the gap.

According to the present invention, by using an annular covering member covering the edge portion of the substrate, the flow path resistance formed in the flow path (gap) between the bottom surface of the covering member and the top surface of the substrate can be reduced, and the suction can be reduced. The burden of the exhaust of the cup. Further, the gas flowing out of the substrate due to the gap formed between the bottom surface of the annular covering member and the top surface of the substrate can effectively prevent the processing liquid supplied to the substrate from scattering from the substrate and then adhering to the substrate again.

1‧‧‧Liquid treatment unit

11‧‧‧Shell

12‧‧ ‧ gate

13‧‧‧Removal of entrance

14‧‧‧Clean air introduction unit

15‧‧‧Exhaust port

2‧‧‧ cup body

21‧‧‧ inner peripheral side

211‧‧‧ top surface

212, 213‧‧‧ gas vents

214‧‧‧ gas introduction line

215‧‧‧ gas diffusion space

216‧‧‧heater

22‧‧‧Processing liquid spout

221‧‧‧Processing fluid supply mechanism

24‧‧‧ peripheral part

241, 242‧‧ ‧ recess

243‧‧‧Separation wall

244‧‧‧Draining road

245‧‧‧Exhaust road

246‧‧‧Exhaust device

247‧‧‧Exhaust port

25‧‧‧Guideboard

251‧‧‧ front end

252‧‧‧ top surface

26‧‧‧ peripheral wall

261‧‧‧ fluid receiving surface

262‧‧‧Delimitation of the wall of the upper part of the cup (bending part)

263‧‧‧ horizontal plane

27‧‧‧Exhaust flow path

3‧‧‧ Wafer Holder

31‧‧‧ wafer adsorption surface

32‧‧ ‧ suction port

41‧‧‧ suction line

42‧‧‧vacuum pump

44‧‧‧Rotary axis

45‧‧‧ bearing housing

451‧‧‧ bearing

46‧‧‧Rotary drive mechanism

461‧‧‧Passive pulley

462‧‧‧ drive pulley

463‧‧‧Drive motor

464‧‧‧Drive belt

5‧‧‧ Covering components

5e‧‧‧ inner edge

51‧‧‧ Covering the inner circumference of the member

511‧‧‧Upper side section

512‧‧‧ lower side section

52‧‧‧Face of the covering member

521‧‧‧ outer edge

53‧‧‧ inner edge

56‧‧‧ recess

58‧‧‧Support

59‧‧‧ Sealing members

6‧‧‧Moving mechanism for covering members

61‧‧‧Sliding parts

62‧‧‧ Guide pillar

63‧‧‧Cylinder motor

631‧‧‧ rod

65‧‧‧ Lifting rod

7‧‧‧Processing Fluid Supply Department

71‧‧‧Processing liquid nozzle (medicine nozzle)

711, 721, 731‧‧ ‧ treatment fluid supply mechanism

72‧‧‧Processing liquid nozzle (cleaning nozzle)

73‧‧‧ gas nozzle

74‧‧‧Nozzle holder

75‧‧‧Cylinder motor

751‧‧‧ rod

8‧‧‧ Controller

81‧‧‧Memory Media

82‧‧‧ Processor

A _R , B _R ‧‧‧Area

G‧‧‧ gap

G ₁ ‧‧‧ Height

G ₂ ‧‧‧Width

R‧‧‧ surface

Rw‧‧‧Rotation direction

W‧‧‧Substrate (wafer)

We‧‧‧outside

Wi‧‧‧ inner edge

Wp‧‧‧Edge

Fig. 1 is a longitudinal side view of a liquid processing apparatus according to an embodiment of the present invention.

Fig. 2 is a plan view showing a covering member of the liquid processing apparatus shown in Fig. 1, an elevating mechanism thereof, and a processing liquid supply unit.

Figure 3 is an enlarged and detailed cross-sectional view showing the vicinity of the outer edge of the wafer on the right side of Figure 1.

Figure 4 (a) - (b) shows the nozzle.

Figure 5 is a view for explaining the flow of the treatment fluid in and around the cup body, (a) is a diagram illustrating the flow of the liquid, and (b) is a diagram illustrating the flow of the gas stream and the mist flowing therethrough.

[Best Mode for Carrying Out the Invention]

As an embodiment of the substrate processing apparatus of the present invention, a HF (Hydro Fluoric Acid) solution is supplied to the surface of the wafer W on which the circular substrate of the semiconductor device is formed, and is removed. A liquid processing apparatus for an unnecessary film of the edge portion of the wafer W will be described.

As shown in FIGS. 1 and 2, the liquid processing apparatus 1 includes a wafer holding unit 3 that holds the wafer W in a horizontal posture so as to be rotatable about a vertical axis, and the cup 2 is held by the wafer holding unit 3. Around the wafer W, the processing liquid scattered from the wafer W is received; the annular covering member 5 covers the edge portion of the top surface of the wafer W held by the wafer holding portion 3; and the lifting mechanism (moving mechanism) 6 The cover member 5 is moved up and down, and the fluid supply unit 7 is processed to supply the processing fluid to the wafer W held by the wafer holding unit 3.

The constituent members of the liquid processing apparatus described above, that is, the cup 2, the wafer holding portion 3, the covering member 5, and the like are housed in one casing 11. A clean air introduction unit 14 that introduces clean air from the outside is provided in the vicinity of the ceiling portion of the casing 11. Further, an exhaust port 15 for discharging the gas in the casing 11 is provided in the vicinity of the bottom surface of the casing 11. Thereby, a downflow of the clean air flowing from the upper portion of the casing 11 toward the lower portion is formed in the casing 11. On the side wall of one side of the casing 11, a removal inlet 13 is opened and closed by the shutter 12. The transfer arm of the wafer transfer mechanism (not shown) provided outside the casing 11 can be moved out of the inlet 13 while holding the wafer W.

The wafer holding portion 3 is configured as a disk-shaped vacuum chuck, and its top surface serves as a wafer adsorption surface 31. A suction port 32 is opened in a central portion of the wafer adsorption surface 31. The hollow cylindrical rotating shaft 44 extends in the vertical direction at the central portion of the bottom surface of the wafer holding portion 3. A suction line 41 (not shown) connected to the suction port 32 passes through the internal space of the rotating shaft 44. This suction line 41 is connected to the vacuum pump 42 on the outer side of the casing 11. The wafer W can be adsorbed by the wafer holding portion 3 by driving the vacuum pump 42.

The rotating shaft 44 is supported by a bearing housing 45 having a bearing 451 built therein, and the bearing housing 45 is supported by the bottom surface of the housing 11. The rotating shaft 44 is driven by the driven pulley 461 on the rotating shaft 44, the driving pulley 462 on the rotating shaft of the driving motor 463, and the driven pulley 461 and the drive. The rotary drive mechanism 46 formed by the drive belt 464 between the movable pulleys 462 can rotate at a desired speed.

As shown in FIG. 3, the cup 2 is provided in such a manner as to surround the outer periphery of the wafer holding portion 3, and has a bottom annular member. The cup 2 has a function of receiving and recovering the chemical liquid supplied to the wafer W and scattering to the outside of the wafer W, and discharging it to the outside.

A small area (for example, 2 to 3 mm) is formed between the bottom surface of the wafer W held by the wafer holding portion 3 and the top surface 211 of the inner peripheral side portion 21 of the cup 2 facing the bottom surface of the wafer W. The gap between the heights of the left and right. Two gas ejection ports 212 and 213 are opened on the top surface 211 opposed to the wafer W. These two gas discharge ports 212, 213, each extending along the circumference of the small radius and the circumference of the large radius of the concentric continuous, radially outward toward and to be inclined upward toward the bottom surface of the wafer W ejection hot N ₂ Gas (heated nitrogen).

One or a plurality of (only one is shown) gas introduction line 214 formed in the inner peripheral side portion 21 of the cup 2 supplies N ₂ gas to the annular gas diffusion space 215, and N ₂ gas is supplied thereto. The gas diffusion space 215 diffuses and flows in the circumferential direction, and is ejected from the gas ejection ports 212 and 213. The heater 216 is provided adjacent to the gas diffusion space 215, and the N ₂ gas is heated while flowing through the gas diffusion space 215, and then is ejected from the gas ejection ports 212 and 213. The N ₂ gas ejected from the gas ejection port 213 located on the outer side in the radial direction accelerates the reaction of the chemical solution by heating the processed portion of the wafer W, that is, the edge portion of the wafer W, and further prevents the crystal from being formed toward the crystal The surface of the circle W (top surface) is a phenomenon in which the mist of the processing liquid scattered after the ejection is returned to the back surface (bottom surface) of the wafer. The N ₂ gas ejected from the gas ejection port 212 located on the inner side in the radial direction is prevented from heating only the edge portion of the wafer W without the gas ejection port 212, and is on the wafer W at the center side of the wafer W. Deformation of the wafer W that may occur under the vicinity of the bottom surface.

In the outer peripheral side portion 24 of the cup body 2, two annular recessed portions 241 and 242 which are open at the upper portion are formed along the circumferential direction of the cup body 2. The recesses 241 and 242 are separated by an annular separating wall 243. The liquid discharge path 244 is connected to the bottom of the outer concave portion 241. Further, an exhaust port 247 is provided at the bottom of the inner concave portion 242, and the exhaust port 247 is connected to the exhaust passage 245. On the exhaust road 245, even An exhaust device 246 such as an ejector or a vacuum pump is connected. In the operation of the liquid processing device 1, the gas in the inner space of the cup 2 is constantly sucked through the exhaust passage 245, and the pressure in the inner concave portion 242 is maintained. The pressure inside the casing 11 outside the cup 2 is lower.

The annular guide sheet 25 extends outward in the radial direction from the outer peripheral portion (the position below the edge of the wafer W) of the inner peripheral side portion 21 of the cup 2. The guide sheets 25 are inclined such that they are lower toward the outer side in the radial direction. The guide sheet 25 covers the entire inner and outer concave portions 242 of the inner concave portion 242 above the inner peripheral side portion thereof, and the front end portion 251 (radially outer side edge portion) of the guide sheet 25 is bent downward and extends toward the outer concave portion 241. In.

Further, the outer peripheral portion of the outer peripheral side portion 24 of the cup body 2 is provided with a peripheral wall 26 continuous with the outer side wall surface of the outer concave portion 241. The outer peripheral wall 26 receives the fluid (droplets, a mixture of gas, and the like) scattered from the wafer W by the inner peripheral surface thereof, and guides the concave portion 241 toward the outer side. The outer peripheral wall 26 has an inner fluid receiving surface 261 which is inclined at an angle of 25 to 30 degrees with respect to the horizontal plane so as to become lower toward the outer side in the radial direction, and a bent portion 262 from the upper end of the fluid receiving surface 261. The section extends downwards. In the illustrated example, the fluid receiving surface 261 as the inclined surface is connected to the bent portion 262 via the horizontal surface 263. However, the curved surface may be provided instead of the horizontal surface 263, or the horizontal surface 263 may not be provided on the fluid receiving surface 261. The upper end portion is directly connected to the bent portion 262. An exhaust gas flow path 27 through which gas (air, N ₂ gas, or the like) and droplets scattered from the wafer W flow is formed between the top surface 252 of the guide sheet 25 and the fluid receiving surface 261. Further, although the upper portion of the cup body 2 is defined by the inner peripheral surface of the bent portion 262, the opening diameter of the upper opening is slightly larger than the diameter of the wafer W.

The mixed fluid of the gas and the liquid droplet which flows into the outer concave portion 241 through the exhaust gas flow path 27 flows between the guide plate 25 and the separation wall 243 and flows into the inner concave portion 242. When passing between the guide plate 25 and the separation wall 243, the flow direction of the mixed fluid is sharply turned, and the liquid (droplet) contained in the mixed fluid collides with the front end portion 251 or the separation wall 243 of the guide sheet 25 to be separated from the fluid. The bottom surface of the guide sheet 25 or the surface of the separation wall 243 is transmitted to flow into the outer concave portion 241, and is discharged from the liquid discharge path 244. The fluid that has removed the droplets and flows into the inner concave portion 242 is discharged from the exhaust passage 245.

The cover member 5 is an annular member that is disposed to face the top edge portion of the wafer W held by the wafer holding portion 3 when the process is performed. The covering member 5, as will be described in detail later, rectifies the gas introduced into the cup body 2 in the vicinity of the edge portion of the top surface of the wafer W, and increases the flow velocity of the gas to prevent scattering from the wafer W. The phenomenon in which the liquid adheres to the wafer W again on the top surface of the wafer W.

As shown in FIG. 3, the covering member 5 has an inner peripheral surface 51 and a bottom surface 52 that is horizontal to the wafer W. The inner circumferential surface 51 has an upper side surface portion 511 extending in the vertical direction, and a lower side surface portion 512 inclined so as to approach the wafer W toward the outer side in the radial direction. A gap G in the vertical direction is formed between the lower side portion 512 and the top surface of the wafer W. The outer edge 521 of the covering member 5 is located radially outward of the outer peripheral end We of the wafer W. Further, the inner edge 53 of the bottom surface 52 of the cover member 5 is located radially inward of the inner edge Wi of the edge portion Wp of the wafer W. Thereby, the airflow passing through the gap G flows horizontally toward the outer side of the wafer W at least in the edge portion Wp of the wafer W. Here, the "edge portion Wp of the wafer W" means an annular region in which no element is formed. The inner edge Wi of the edge portion Wp of the wafer W is a circle formed outside the center of the wafer W, that is, a circle centered on the center of the wafer W, and has the following conditions The circle of the smallest radius: outside the circle, there is no element formation region at all. The radial direction width of the edge portion Wp of the wafer W, that is, the radial direction from the outer peripheral end We of the wafer W to the inner edge Wi of the edge portion Wp of the wafer W is, for example, about 3 mm.

FIG. 2 is a plan view showing a state in which the wafer holding portion 3 holds the wafer W and the covering member 5 is at the processing position. In FIG. 2, the outer peripheral end (edge) We of the wafer W which is covered by the covering member 5 and hidden is indicated by a dotted line. Further, the inner edge of the covering member 5 is indicated by the symbol 5e. By opening the central portion of the covering member 5 in this manner, the flow path formed between the bottom surface of the covering member and the wafer W is compared with a conventional disk-shaped covering member covering almost the entire surface of the wafer. Since the road resistance becomes small, sufficient suction can be performed even if the gas venting ability of the gas in the inner space of the suction cup 2 is low. Further, most of the top surface of the wafer W is not covered by the covering member 5 except for the edge portion, and the surface of the wafer W being processed can be monitored by, for example, providing a camera in the casing 11. In addition, by providing a transparent window in the casing 11, the wafer W in process can also be visually observed. The surface.

As shown in FIGS. 1 and 2, the elevating mechanism 6 for elevating and lowering the covering member 5 includes a plurality of (four in this example) sliding members 61 attached to the supporting body 58 supporting the covering member 5, and through the sliding members 61. The guide post 62 extends in the vertical direction. A linear actuator such as a rod 631 of the cylinder motor 63 is coupled to each of the sliders 61. By driving the cylinder motor 63, the slider 61 is moved up and down along the guide post 62, whereby the cover member 5 can be moved up and down. The cup 2 is supported by a lifting rod 65 constituting a part of a cup lifting mechanism (not shown in detail). When the lifting rod 65 is lowered from the state shown in Fig. 1, the cup 2 is lowered and can be transported on the wafer. The transfer of the wafer W is performed between the transfer arm (not shown) of the mechanism and the wafer holding unit 3.

Next, the processing fluid supply unit 7 will be described with reference to Figs. 1, 2, and 4. In particular, as shown in Fig. 2, the processing fluid supply unit 7 includes a chemical liquid nozzle 71, a discharge chemical solution (HF in this example), a cleaning nozzle 72, a discharge cleaning liquid (in this example, DIW (pure water)), and a gas. The nozzle 73 is a gas for drying and discharging (in this example, N ₂ gas). The chemical liquid nozzle 71, the cleaning nozzle 72, and the gas nozzle 73 are attached to the common nozzle holder 74. The nozzle holder 74 is mounted on a rod 751 of a linear actuator such as a cylinder motor 75 to which the support body 58 supporting the cover member 5 is mounted. By driving the cylinder motor 75, the supply position of the processing fluid from the nozzles 71 to 73 onto the wafer W can be moved in the radial direction of the wafer W.

As shown in FIGS. 2 and 4( a ), the nozzles 71 to 73 are housed in a recess 56 formed on the inner circumferential surface of the cover member 5 . Each of the nozzles (71 to 73) ejects the processing fluid so as to be obliquely downward as indicated by an arrow A in Fig. 4(b), and the ejection direction indicated by the arrow A has a composition in the rotation direction Rw of the wafer. Thereby, it is possible to suppress the occurrence of mist (caused by the treatment liquid and the wafer W) which may occur in the case where the treatment fluid is a liquid. The processing fluids supplied from the processing fluid supply mechanisms 711, 721, and 731 shown schematically in FIG. 2 are supplied to the respective nozzles (71 to 73). Each of the processing fluid supply mechanisms 711, 721, and 731 may be configured by a supply of a processing fluid such as a storage tank, a conduit for supplying a processing fluid from a processing fluid supply source to a nozzle, and an opening and closing valve or flow rate provided in the pipeline. Adjust flow control components such as valves.

Further, as shown in FIG. 3, in the inner peripheral side portion 21 of the cup body 2, a plurality of (only one of them is shown) processing liquid ejection ports 22 in the circumferential direction are provided on the outer side of the gas ejection opening 213. The location of the difference is formed. Each of the processing liquid ejection ports 22 is directed toward the bottom edge portion of the wafer W, and ejects the processing liquid obliquely upward toward the outside of the wafer W. The chemical liquid which is the same as the chemical liquid which is ejected from the chemical liquid nozzle 71 can be ejected from at least one of the processing liquid ejection ports 22. Further, the same cleaning liquid as the cleaning liquid sprayed from the cleaning nozzle 72 can be ejected from at least one of the other processing liquid ejection ports 22. As shown in FIG. 3, each of the processing liquid ejection ports 22 is connected to a processing fluid supply mechanism 221 having the same configuration as the nozzles 71 to 73.

As schematically shown in Fig. 1, the liquid processing apparatus 1 has a controller (control unit) 8 that collectively controls the overall operation thereof. The controller 8 controls the operations of all the functional components of the liquid processing apparatus 1 (for example, the rotary drive mechanism 46, the elevating mechanism 6, the vacuum pump 42, and various processing fluid supply mechanisms). The controller 8 can be realized by, for example, a general-purpose computer as a hardware, a program for operating the computer (a device control program, a processing recipe, etc.) as a software. The software is stored in a memory medium such as a hard disk fixed on a computer, or in a memory medium that is detachably mounted on a computer such as a CD-ROM, a DVD, or a flash memory. These memory media are indicated by reference numeral 81 in FIG. The processor 82 calls out and executes a predetermined processing recipe from the memory medium 81 in response to an instruction from a user interface (not shown), thereby enabling the functional components of the liquid processing apparatus 1 under the control of the controller 8. Act and perform the given process.

Next, the operation of the liquid processing apparatus 1 performed under the control of the controller 8 will be described.

[wafer transfer]

First, the covering member 5 is placed at the retracted position (a position higher than that of FIG. 1) by the elevating mechanism 6, and the cup 2 is lowered by the elevating rod 65 of the cup lifting mechanism. Next, the shutter 12 of the casing 11 is opened, and a transfer arm (not shown) of an external wafer transfer mechanism (not shown) enters the casing 11, and the wafer W held by the transfer arm is placed on the wafer holder. Directly above 3. Next, the carrier arm is lowered to a position lower than the top surface of the wafer holder 3, and the wafer W is placed on the top surface of the wafer holder 3. Then, the wafer is adsorbed by the wafer holder 3. After that, make it empty The carrying arm is withdrawn from the housing 11. Next, the cup 2 is raised to return to the position shown in Fig. 1, and the covering member 5 is lowered to the processing position shown in Fig. 1. By the above procedure, the wafer is moved in and the state shown in Fig. 1 is obtained.

[medicine treatment]

Secondly, the liquid chemical treatment for the wafer is performed. The wafer W is rotated at a predetermined speed (for example, 2000 rpm), and the hot gas N ₂ gas is ejected from the gas ejection ports 212 and 213 of the cup ₂ , and the wafer W, particularly the processed region, that is, the edge portion of the wafer W, is Heat to a temperature suitable for the chemical treatment (for example, about 60 ° C). In addition, in the case where the heating of the wafer W is not necessary, the N ₂ gas at a normal temperature may be discharged without causing the heater 216 to operate. After the wafer W is sufficiently heated, the wafer W is rotated to supply the chemical liquid (HF) from the chemical liquid nozzle 71 to the edge portion of the top surface (element forming surface) of the wafer W, and the top surface of the wafer is removed. Unwanted film at the edge. At the same time, the chemical liquid discharge port 22 supplies the chemical liquid to the bottom edge portion of the wafer W, and removes an unnecessary film located at the edge portion of the bottom surface of the wafer. The chemical liquid supplied to the upper and lower sides of the wafer W is diffused and flows outward by centrifugal force, and flows out to the outside of the wafer W together with the removed material, and is recovered by the cup 2. Further, when the chemical liquid treatment is performed, the cylinder motor 75 is driven in response to the demand, and the chemical liquid nozzle 71 for discharging the chemical liquid is reciprocated in the radial direction of the wafer W, whereby the uniformity of the processing can be improved.

[cleaning treatment]

After the chemical liquid treatment for a predetermined period of time, the rotation of the wafer W and the ejection of the N ₂ gas from the gas ejection ports 212 and 213 are continued, and the chemical liquid from the chemical liquid nozzle 71 and the processing liquid ejection opening 22 for the chemical liquid is stopped. In the ejection, the cleaning liquid (DIW) is supplied to the edge portion of the wafer W from the cleaning nozzle 72 and the processing liquid ejection port 22 for the cleaning liquid, and the cleaning process is performed. By this cleaning process, the chemical liquid, the reaction product, and the like remaining on the upper surface of the wafer W are removed.

[drying treatment]

After the cleaning process for a predetermined period of time, the rotation of the wafer W and the ejection of the N ₂ gas from the gas ejection ports 212 and 213 are continued, and the ejection of the cleaning liquid from the cleaning nozzle 72 and the processing liquid ejection port 22 for the cleaning liquid is stopped. The drying gas (N ₂ gas) is supplied from the gas nozzle 73 to the edge portion of the wafer W, and is subjected to a drying process. The series of processes for the wafer W is terminated by the above procedure.

[wafer removal]

Then, the covering member 5 is raised to be at the retracted position and the cup 2 is lowered. Next, the shutter 12 of the casing 11 is opened, and a transfer arm (not shown) of an external wafer transfer mechanism (not shown) enters the casing 11, and the empty transfer arm is held by the wafer holder 3. After the wafer W is lifted down, the wafer holder 3 receives the wafer W from the state in which the transfer arm is stopped by the wafer W. Thereafter, the transfer arm holding the wafer is withdrawn from the housing 11. By the above, a series of procedures in the liquid processing apparatus for one wafer is ended.

Next, the flow of the fluid in the vicinity of the edge portion of the wafer during the chemical treatment, and the configuration of the cup 2 and the covering member 5 relating to the flow of the fluid will be described in detail with reference to FIGS. 3 to 5.

Since the gas in the inner space of the cup 2 is sucked by the exhaust passage 245 to be a negative pressure, the gas located above the top surface of the wafer W (the clean air that forms the downflow in the casing 11) passes through the gap. G is introduced into the exhaust flow path 27 in the cup 2. Further, the N ₂ gas ejected from the gas ejection ports 212 and 213 flows out from the space between the top surface 211 of the inner circumferential side portion 21 of the cup body 2 and the bottom surface of the wafer W due to the influence of the rotation of the wafer W. To the outside, it flows into the exhaust flow path 27. The flow of these gases is shown in Figure 5(b).

The lower side surface portion 512 of the inner circumferential surface 51 of the covering member 5 is inclined so as to approach the wafer W toward the outer side in the radial direction (that is, the inner diameter of the lower portion of the inner peripheral surface 51 of the covering member 5 is larger toward the lower side. In this manner, the gas flows smoothly into the gap G as compared with the case where the inner peripheral surface 51 is a single vertical surface, and disturbance of the airflow is hard to occur in the gap G. Further, the connecting portion of the inner circumferential surface 51 and the bottom surface 52 of the covering member 5 is not an edge (the inner edge 53 indicated by reference numeral 53 in Fig. 3), and the inner circumferential surface 51 and the bottom surface 52 may be curved (refer to the figure). 5(b) is an arrow of the additional symbol R), and the shape of these R is also preferable in that the gas flows smoothly into the gap G.

On the other hand, the chemical liquid supplied from the chemical liquid nozzle 71 to the edge of the top surface of the wafer W and the chemical liquid supplied from the processing liquid discharge port 22 for the chemical liquid to the bottom edge portion of the wafer W are centrifugally driven. Spread toward the edge of the wafer and fly away from the wafer W. The majority of the chemical liquid on the top surface of the wafer W is scattered toward the area A _R surrounded by the two arrows A ₁ and A ₂ on the upper side in Fig. 5(a). The chemical liquid is scattered in the horizontal direction (the direction of the arrow A ₁ ) at most and strongly, and the closer the scattering direction is to the direction indicated by the arrow A ₂ , the smaller the amount and the force of the scattered chemical liquid. The majority of the chemical solution on the bottom surface of the wafer scatters toward the region B _R sandwiched by the two arrows B ₁ and B ₂ on the lower side in Fig. 5(b). The chemical solution is scattered in the horizontal direction (the direction of the arrow B ₁ ) at most and strongly, and the closer the scattering direction is to the direction indicated by the arrow B ₂ , the smaller the amount of the scattered chemical liquid and the force path. In the case where the chemical liquid is scattered, the influence of the flow of the gas (clean air) flowing out in the horizontal direction when the gap G between the covering member 5 and the wafer W is increased by the centrifugal force is added. . Further, the liquid (chemical liquid, cleaning liquid) supplied to the top surface of the wafer W does not contact the bottom surface 52 of the covering member 5.

The chemical liquid scattered from the wafer W flows down along the fluid receiving surface 261 and the top surface 252 of the guide sheet 25 toward the concave portion 241 on the outer side of the cup body 2, or becomes a fine droplet (mist) and rides on FIG. The airflow in the exhaust gas flow path 27 shown in (b) flows. In Fig. 5(b), an arrow indicated by a broken line indicates an air flow, and the flow of the mist in the exhaust flow path 27 closely coincides with the flow in the exhaust flow path 27. Further, even if the liquid droplets located in the exhaust gas flow path 27 pass through the gap G between the bottom surface 52 of the covering member 5 and the top surface of the wafer W and proceed to the center portion of the wafer W, the movement of the liquid droplets is also caused by The airflow flowing in the gap G toward the outside of the wafer W is hindered. Therefore, contamination of the wafer W due to the phenomenon that the chemical solution scattered from the wafer W is reattached can be prevented.

In addition to the above-described configuration, the cup body 2 and the covering member 5 of the present embodiment have the following advantageous configuration in order to prevent the wafer W from being contaminated by the phenomenon in which the chemical solution scattered from the wafer W re-adheres.

In order to prevent the splash of the chemical liquid incident on the fluid receiving surface 261 of the cup 2 with a strong force, the angle of the fluid receiving surface 261 of the cup 2 to the horizontal plane (this angle and the liquid liquid indicated by the arrows A ₁ and B ₁ ) The flow incidence is the same as the incident angle θ of the fluid receiving surface 261, and is set to a small value, for example, 30 degrees. Thereby, the scattering of the chemical solution caused by the collision of the chemical liquid with the fluid receiving surface 261 is reduced.

A gap G between the bottom surface 52 of the covering member 5 and the top surface of the wafer W, the opening area of the gap G (meaning that the distance from the central axis of the covering member 5 to the inner edge 53 of the bottom surface 52 is equal) The radius and the height G ₁ (the area of the cylindrical surface of the gap G) are set to be equal to or larger than the area of the exhaust port 247. Thereby, the introduction of the gas located above the top surface of the wafer W can be smoothly performed. When the gap G is too narrow, the flow path resistance of the gap G becomes large, and sufficient suction cannot be performed with a slight exhaust force. The height G _{1 of the} gap G can be, for example, 4 to 5 mm.

Further, the radial width G _{2 of} the gap G (the length of the bottom surface of the covering member 5 and the wafer W overlapping in the radial direction) is 4 to 6 mm, for example, about 5 mm. When the width G ₂ of the gap G is excessively large, the flow path resistance of the gap G becomes large, and sufficient suction cannot be performed with a slight exhaust force. On the other hand, if the width G _{2 is} too small, the flow of the gas in the gap G is disturbed, which is unsuitable (the gas in the gap G preferably flows horizontally outward in the radial direction). In addition, the optimum value of the width G ₂ is changed in relation to the height G ₁ .

The distance D ₁ between the fluid receiving surface 261 and the top surface 252 of the guide sheet 25 gradually decreases toward the downstream side (with the concave portion 241 on the outer side of the cup 2). By doing so, it is possible to suppress the generation of the flow of the reverse flow.

Since the cup portion 2 is provided with the bent portion 262, it is assumed that even if a reverse flow of the air flow indicated by the arrow F _R1 in FIG. 5(b) is generated, the reverse flow is caused by the bent portion 262 as shown by the arrow F _R2 . Since the downstream side of the air path 245 is turned, the mist of the chemical liquid which is carried by the air flow indicated by the arrow F _R1 is prevented from being directed toward the wafer W.

Further, it is preferable that the height of the front end (lower end) of the bent portion 262 of the cup 2 is the same as the height of the bottom surface 52 of the covering member 5. If they are made the same, it is difficult to cause disturbance in the flow of the gas passing through the gap G. Although the difference between the heights is allowed in the two, if the front end of the bent portion 262 is located at an excessively low position, there is a mist of the chemical liquid scattered from the surface of the wafer W (refer to arrow A _{2 of} FIG. 5(a)). The collision with the bent portion 262 causes the wafer W to splash. On the other hand, if the front end of the bent portion 262 is located at an excessively high position, the mist of the chemical liquid which is multiplied by the air current indicated by the arrow F _R1 in Fig. 5(b) cannot be sufficiently prevented from being directed toward the wafer W. In addition, the distance between the edge 521 of the bottom surface 52 of the cover member 5 and the bent portion 262 (the distance measured in the radial direction of the wafer) is not as close to the cup 2 as the cover member 5 is lifted and lowered as much as possible. In the collision, it should be reduced as much as possible. Thereby, the gas passing through the gap G is prevented from forming a vortex in the space between the edge 521 and the bent portion 262.

When the covering member 5 is placed at the processing position, as shown in FIG. 3, it is preferable to seal the covering member 5 and the top surface of the outer peripheral wall 25 by the sealing member 59. As a result, the gas in the casing 11 is introduced into the exhaust gas flow path 27 through the gap G, so that the airflow disturbance near the outer edge of the wafer W is less likely to occur, and the exhaust device 246 can be further alleviated. burden.

In addition, although the flow of the gas flow and the mist is described by taking the chemical liquid treatment as an example, it is understood that the flow of the same gas flow and the mist also occurs during the cleaning process.

The liquid treatment performed by the liquid processing apparatus 1 is not limited to the above-described type. For example, the chemical solution is not limited to HF, and may be SC-1 or SC-2, and a plurality of chemical liquid treatments may be performed. Further, the substrate to be processed is not limited to a semiconductor wafer, and may be various circular substrates requiring cleaning of the edge portion, such as a glass substrate, a ceramic substrate, or the like.

21‧‧‧ inner peripheral side

211‧‧‧ top surface

212, 213‧‧‧ gas vents

214‧‧‧ gas introduction line

215‧‧‧ gas diffusion space

216‧‧‧heater

22‧‧‧Processing liquid spout

221‧‧‧Processing fluid supply mechanism

24‧‧‧ peripheral part

241, 242‧‧ ‧ recess

243‧‧‧Separation wall

244‧‧‧Draining road

245‧‧‧Exhaust road

246‧‧‧Exhaust device

247‧‧‧Exhaust port

25‧‧‧Guideboard

251‧‧‧ front end

252‧‧‧ top surface

26‧‧‧ peripheral wall

261‧‧‧ fluid receiving surface

262‧‧‧Delimitation of the wall of the upper part of the cup (bending part)

263‧‧‧ horizontal plane

27‧‧‧Exhaust flow path

5‧‧‧ Covering components

5e‧‧‧ inner edge

51‧‧‧ inner circumference

511‧‧‧Upper side section

512‧‧‧ lower side section

52‧‧‧Face of the covering member

521‧‧‧ outer edge

53‧‧‧ inner edge

58‧‧‧Support

59‧‧‧ Sealing members

G‧‧‧ gap

We‧‧‧outside

Wi‧‧‧ inner edge

Wp‧‧‧Edge

Claims (10)

A substrate processing apparatus includes: a substrate holding portion that holds a substrate horizontally; a rotation driving mechanism that rotates the substrate holding portion about a vertical axis; and a processing liquid nozzle that supplies an edge portion of a top surface of the substrate held by the substrate holding portion a treatment liquid; the cup body surrounds the periphery of the substrate held by the substrate holding portion, and recovers the treatment liquid scattered from the substrate; the exhaust port is used for suctioning the gas in the inner space of the cup; and the annular cover The member has a bottom surface and an inner peripheral surface; and the covering member covers an edge portion of a top surface of the substrate held by the substrate holding portion, and the covering member does not cover a center of the substrate located radially inward of the edge portion The bottom surface of the cover member forms a gap between the edge portion of the top surface of the substrate held by the substrate holding portion, and when the inner space of the cup is exhausted, the cup is placed in the cup The gas above the inner space is introduced into the inner space of the cup through the gap through the space surrounded by the inner peripheral surface of the covering member. The substrate processing apparatus according to claim 1, wherein an inner diameter of a lower portion of the inner peripheral surface of the covering member increases toward the lower side. The substrate processing apparatus according to claim 2, wherein the lower end portion of the inner peripheral surface of the covering member and the inner peripheral portion of the bottom surface are connected by a curved surface. The substrate processing apparatus according to any one of claims 1 to 3, wherein an inner edge of the bottom surface of the covering member is located further inside than an outer peripheral end of the substrate held by the substrate holding portion, the covering member The outer edge of the bottom surface is located further outside than the outer edge of the substrate held by the substrate holding portion. The substrate processing apparatus of claim 4, wherein an inner edge of the bottom surface of the covering member is located further inside than an inner edge of the edge portion of the substrate held by the substrate holding portion. The substrate processing apparatus according to any one of claims 1 to 3, wherein an opening area of the gap is larger than an area of the exhaust port. The substrate processing apparatus according to any one of claims 1 to 3, wherein the cup has an upper opening portion inserted into a lower portion of the covering member, and a wall body forming the upper opening portion of the cup body, Set the bend that extends downward. The substrate processing apparatus according to any one of claims 1 to 3, wherein the covering member further includes a moving mechanism that is close to a processing position and a distance from a top surface of the substrate held by the substrate holding portion The substrate is moved between the retracted positions. A substrate processing method comprising the steps of: maintaining a substrate horizontally by covering an upper surface of the substrate with a ring-shaped covering member around the substrate, and arranging the inner space of the cup body; a step of supplying a processing liquid to an edge portion of the substrate in a state where the substrate is rotated about a vertical axis, and performing a liquid treatment on the substrate; wherein the covering member covers the substrate holding portion when the substrate is subjected to liquid processing The edge portion of the top surface of the substrate is not covered, and the covering member does not cover the central portion of the substrate located radially inward of the edge portion to be exposed, and the bottom surface of the covering member and the edge portion of the top surface of the substrate Forming a gap therebetween, by exhausting the inner space of the cup body, the gas located above the covering member is introduced into the cup body through a space surrounded by the inner circumferential surface of the covering member and the gap The interior space. The substrate processing method according to claim 9, wherein the gas flows horizontally outward toward the outside between the bottom surface of the covering member and the edge portion of the top surface of the substrate.